1. Field of the Invention
The present invention relates to a socket for holding a base part of an electric lamp bulb.
2. Description of the Related Art
For example, PTL 1 discloses a structure of a socket having a frame body in a tubular shape into which a base part of an electric lamp bulb is inserted. In the frame body of this socket, a pair of terminal metal fittings which are electrically connected to the bulb, while clamping the base part of the bulb with pressure. The frame body of the socket is formed in a rectangular shape in conformity with the base part of the bulb. A pair of opposed side walls of this frame body are respectively provided with two slits extending from open ends of the side walls along an axial direction of the frame body. An arm piece for elastically supporting each of the terminal metal fittings is formed between these two slits. The terminal metal fitting has a folded part which is projected in a V-shape into the frame body.
In the above described structure, when the base part of the bulb is inserted into the frame body, convex parts which are respectively formed on opposed faces of the base part come into contact with the folded parts of the terminal metal fittings thereby to deform the folded parts. By further deeply inserting the convex parts, the folded parts which have been deformed press the arm pieces, and are spread outward together with the arm pieces, thereby allowing the convex parts to override the folded parts. As the convex parts are pushed in, the base part of the bulb is pressed with the terminal metal fittings from both sides, and the folded parts are positioned behind the convex parts. In this manner, the bulb is retained inside the frame body. According to this structure, when the base part is inserted into the frame body, the arm pieces are spread along with deformation of the terminal metal fittings. As the results, it is possible to prevent excessive deformation of the terminal metal fittings, and also to restrain permanent deformation of the terminal metal fittings.